<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<script>
    var arr =[3,2,1,4];

    for(var j=0; j<arr.length-1; j++){
        for(var i=0; i<arr.length-1; i++){
            if(arr[i] > arr[i+1]){
                var temp = arr[i];
                arr[i] = arr[i+1];
                arr[i+1] = temp;
            }
        }
    }
    console.log(arr);
</script>
</body>
</html>